The conventional printer is generally divided into the laser printer and the light emitting diode (LED) printer according to the difference of their light source. Comparing the laser printer and the light emitting diode printer, the LED light source has a longer service life and lower power consumption. Moreover, heat generated by the LED light source is relatively low so that the requirements of the heat dissipation component can be reduced, thereby reducing noise while the printer is in operation. In addition, the LED printer has no need to be equipped with a complicated optical structure so that the LED printer has high durability and reliability. The size of the LED printer can be smaller than the size of the laser printer, and more functions can be integrated into the LED printer. Therefore, the LED printer has become the mainstream product.
In detail, an imaging apparatus of a conventional printer includes a photosensitive drum and a toner cartridge. Generally, the traditional photosensitive drum and the traditional toner cartridge are inseparable. In such a design, a distance between the photosensitive drum and the toner cartridge can be controlled precisely so that the imaging quality can be controlled easily. In recent years, with the raise of environmental awareness, some of printer manufacturers start to design a changeable toner cartridge, which is consumable, and let the photosensitive drum, which is not consumable, can be used repeatedly; therefore, the imaging apparatus becomes disassemblable.